The recently increasing global concern about sustainability and greenhouse gas
emission reduction has boosted the diffusion of electric vehicles. Research on
this topic mainly focuses on either re-designing or adapting most conventional
vehicle subsystems, especially the propulsion motor and the braking
components.
In this context, the present work aims to model, analyze, and compare
three-braking system layouts design alternatives focusing on their contribution
to vehicle performance and efficiency: a commercial vacuum-boosted hydraulic
braking system, a commercial integrated electrohydraulic braking system, and a
concept distributed electrohydraulic brake system. Braking systems performance
are evaluated by simulating key maneuvers adopting a full model of a battery
electric vehicle (BEV), which includes all relevant components like tires, and
powertrain dynamics, which is validated against real-world data. Implementation
and integration of the first two systems are discussed, followed by the design
and detailed modeling of the third, which includes a control strategy for
pressure modulation, including antilock braking system (ABS) and electronic
stability control (ESC) functionalities. Once the simulation environment is set,
simulations are performed and KPIs are defined to compare the three braking
systems from both the performance and the energy consumption point of view. The
results show that the distributed electrohydraulic system reduces the time to
lock by 30.8%, the stopping distance by 5.89%, and the energy consumption by
more than 50% in specific test cases compared to the analyzed vacuum-boosted
system due to its distributed hardware and control architecture and
power-on-demand operation.